Submission #1016463

#	Time	Username	Problem	Language	Result	Execution time	Memory
1016463		vjudge1	Combo (IOI18_combo)	C++17	0 / 100	1 ms	344 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;

string guess_sequence(int N) {
	string s = "";
	string chars;
	// find first button
	int f = press("AB");
	if(f==1){
		int ff = press("A");
		if(ff==1) {
			chars = "BXY";
			s = "A";
		}
		else{
			chars = "AXY";
			s = "B";
		}
	}
	else{
		int ff = press("X");
		if(ff==1){
			chars = "ABY";
			s = "X";
		}
		else{
			chars = "ABX";
			s = "Y";
		}
	}
	
	// find 2nd to 2nd last button
	for (int i=2; i<N; i++){
		string qry = s+chars[1] + s+chars[2]+chars[0] + s+chars[2]+chars[1] + s+chars[2]+chars[2];
		int coins = press(qry);
		if(coins==i-1) s += chars[0];
		else if(coins==i) s += chars[1];
		else s += chars[2];
	}
	
	// find last button
	int l = press(s+chars[0]);
	if(l==N) s += chars[0];
	else{
		int ll = press(s+chars[1]);
		if(ll==N) s += chars[1];
		else s += chars[2];
	}
	return s;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 95